16 min. Litchi Mission ...

Avocet · Jul 11, 2018

Inspire 1 v2.0 with a T48 battery, winds < 8mph <150ft AGL --- 16 minutes should be well in the endurance envelope, no?

I would fly this in my P3P methinks (a little nervous) most likely as I've done so many times.

No worries????

I'm usually very conservative and over-plan. BTW, thought it doesn't matter much, but 90% of this is over salt water.

Your thoughts?

The Editor · Jul 11, 2018

Avocet said:
Inspire 1 v2.0 with a T48 battery, winds < 8mph <150ft AGL --- 16 minutes should be well in the endurance envelope, no?

I would fly this in my P3P methinks (a little nervous) most likely as I've done so many times.

No worries????

I'm usually very conservative and over-plan. BTW, thought it doesn't matter much, but 90% of this is over salt water.

Your thoughts?

Depends on the state of your batteries!
I would say to expect 16minutes comfortably (with some margin) out of a used TB48 is pushing things more than I personally would advocate.

Avocet · Jul 11, 2018

The Editor said:
Depends on the state of your batteries!
I would say to expect 16minutes comfortably (with some margin) out of a used TB48 is pushing things more than I personally would advocate.

Thanks for the note. It is a new T48 with less than 3 charges on it (shake downs, really). For this mission, I have changed some legs set to "cruising", which is set to 20mph. This brought the total time/distance to 14min/2.6m. I've got some ideas for testing purposes that mitigates the risk.

What is your personal threshold for time in the air on a newish T48 assuming very good flying conditions? Thank once more, good sir,

The Editor · Jul 12, 2018

Avocet said:
Thanks for the note. It is a new T48 with less than 3 charges on it (shake downs, really). For this mission, I have changed some legs set to "cruising", which is set to 20mph. This brought the total time/distance to 14min/2.6m. I've got some ideas for testing purposes that mitigates the risk.

What is your personal threshold for time in the air on a newish T48 assuming very good flying conditions? Thank once more, good sir,

I would say 14-14.5mins would be fine and allows for a margin of safety but 16mins (even on a new TB48) on an autonomous flight might be pushing into the ''no reserve if you needed it" territory.

Eric Braun · Jul 14, 2018

Just try it. If the battery gets low break out of the mission and land. Then you’ll know.

The Editor · Jul 14, 2018

Eric Braun said:
Just try it. If the battery gets low break out of the mission and land. Then you’ll know.

He said his mission was 90% over water so landing if battery drops suddenly isn’t really an option

Eric Braun · Jul 14, 2018

The Editor said:
He said his mission was 90% over water so landing if battery drops suddenly isn’t really an option

Well... right... not over water for a test flight.

CSpenceFLY · Jul 14, 2018

another factor is what camera or payload will you be carrying?

Steve@AerialImagesPro · Jul 15, 2018

Flight time also depends on wind direction, speed and if wind is gusty that's the worst for battery life. I would think, over water would be pretty windy. Why cant you break it into 2 missions? Or is it 8 minutes out and 8 minutes back?, in which case I wouldn't touch that mission unless I was making enough to cover a total loss of the bird.

Avocet · Jul 16, 2018

Steve@AerialImagesPro said:
Flight time also depends on wind direction, speed and if wind is gusty that's the worst for battery life. I would think, over water would be pretty windy. Why cant you break it into 2 missions? Or is it 8 minutes out and 8 minutes back?, in which case I wouldn't touch that mission unless I was making enough to cover a total loss of the bird.

Steve ... 8 out, 8 back, this is a filming mission. It's also an amended mission that was 6.5 out and 6.5 back, nearly same subject matter, and was done easily with a P3P, landing with 44% and was a terrific success (lacking humility this morning).

Due to obvious risk and subject redundancy, I've decided to scrap this one and move on. Originally I was planning on using a new Inspire for this but decided to use a P3P (free to me but needed some minor repairs) instead. As it is still a quite capable camera platform, I'm moving on. Thanks for the note.

Steve@AerialImagesPro · Jul 16, 2018

It always sucks, big time, to turn down a gig, so I feel for you. I've had to turn some down (one where a guy wanted to get a shot flying THROUGH one of those giant building cranes while it was moving!).

Sometimes it's better to fold a good hand when raised if there is a small chance you you could get beat to protect your stack

I think you made the right choice which many times is the difference between an amateur and a pro (risk analysis).